Occupational physical activity is related to physical fitness in young workers.

PURPOSE: We evaluated the association between occupational physical activity and fitness in young workers, taking into account leisure-time physical activity, body size, and smoking. METHODS: The study population comprised 2188 men and 1987 women, members of the Northern Finland birth cohort 1966, who participated in the 1997-1998 follow-up survey and were employed at the time of the survey. Cardiorespiratory fitness was measured by a 4-min step test and muscular fitness by tests of maximal isometric handgrip and isometric trunk extension. Information on occupational and leisure-time physical activity and smoking was obtained by questionnaire, and body height and weight were measured during medical examination. The data were analyzed by analysis of variance and Cox regression. RESULTS: Men doing heavy physical work scored better in cardiorespiratory fitness, handgrip strength, and trunk muscle endurance than men doing lighter work; the finding for cardiorespiratory fitness was similar in women. The associations were independent of leisure-time physical activity, body weight and height, and smoking. CONCLUSION: A positive association was found between heavy physical work and a high level of fitness in young workers. Due to limitations of the study setting, causality cannot be asserted, but a training effect of heavy work would not seem unreasonable. Previous studies have suggested a reversal of the positive effect of heavy work on fitness with advancing age. Therefore, regular monitoring of workers' fitness at an early phase is justified to enable assessment of workers' capacity for heavy jobs and any possible need for fitness-improving activities.     

Feasibility of power-type strength training for middle aged men and women: self perception,musculoskeletal symptoms,and injury rates

OBJECTIVES: To examine the feasibility of a power-type strength training programme for middle aged men and women, the impact of the training programme on perceived health and fitness and on knee and low back symptoms, and the rate of exercise induced injuries. METHODS: A total of 154 voluntary, healthy, sedentary men and women participated in a training programme lasting about four months. The explosive force of leg extensor muscles was measured by means of standing long jumps and vertical squat jumps. Perceived health, perceived fitness, and low back and knee symptoms were assessed before and after the intervention by using a questionnaire. Musculoskeletal disorders and exercise induced injuries were reported during the training programme. RESULTS: Perceived fitness improved in both men (p<0.01) and women (p<0.0001), but perceived health only in women (p<0.01). Men with increased explosive force in squat jumping also showed better perceived health (p<0.05), and women with increased explosive force in standing long jump showed better perceived fitness (p<0.05). Exercising men who had increased knee symptoms had significantly higher body mass index than the other exercising men (p<0.05). The exercise induced injury rate was 19% in men and 6% in women. CONCLUSIONS: Successful completion of the exercise programme, together with the increased physical activity and relatively low injury rate, may have contributed to the participants finding the exercise programme positive and stimulating and believing that their health and fitness had improved. The low rate of musculoskeletal injury suggests that this type of supervised exercise programme is feasible for untrained middle aged people.     

Symptom-limited graded treadmill exercise testing in young adults in the CARDIA study.

Symptom-limited, graded exercise treadmill testing was performed by 4,968 white and black adults, ages 18-30 yr, during the baseline examination for the CARDIA study. The mean estimated maximal exercise capacity by race/gender, expressed as metabolic units (METS), was: white men 13.8, black men 13.0, white women 11.1, and black women 9.4. Exercise test duration was higher in nonsmokers, positively related to physical activity score and pulmonary function (FEV1.ht-2), and inversely related to body mass index. Men had higher mean values than women for both test duration and a measure of submaximal performance, the workload 130 (WL130, the exercise test duration to a heart rate of 130 beats.min-1). Adjusted for age and education, white men had a longer mean test duration than black men (53 s longer, P less than 0.001), but nearly equal mean WL130. White women had higher mean values than black women for both test duration (114 s longer, P less than 0.001) and WL130 (36 s longer, P less than 0.001). Men had higher mean values than women for both outcome measures (P less than 0.001). Thus, in young adults significant gender and ethnic differences exist for exercise test performance, part of which can be explained by personal habits or traits.     

Relationship of sexual abuse to motivation for strenuous exercise

AIM: Sources of motivation for intense physical exercise are poorly understood. Based on views that link such behaviour to preexisting psychopathology, we tested the hypotheses that history of childhood sexual abuse would be greater in intense exercisers than in non-exercisers, and that effects of abuse on self-esteem, perfectionism and body dissatisfaction would help to explain any link between abuse and exercise. METHODS: Consecutive attenders at two types of exercise were recruited: weight training and running. Sedentary attenders at a further education college provided a third, comparison group. Each group contained 64 men and 64 women. Participants completed questionnaires to record history of sexual and physical abuse in childhood and adulthood, body dissatisfaction, self-esteem, and positive and negative perfectionism. RESULTS: Adult, but not childhood abuse, was reported by more weight-trainers than others. Abused individuals were more anxious and depressed, were more negative about themselves and were more concerned with avoiding failure in general. Women abused in childhood were more concerned with avoiding failure at exercise in particular. CONCLUSION: These results suggest hypotheses that link adult abuse to intense weight training habits and, in women, that link child abuse to feelings of failure in exercise.     

Prevalence of injuries among young adults in sport centers: relation to the type and pattern of activity

The rate of injuries resulting from physical exercise in sport centers as well as related factors has not yet been described. The aims of this study were to describe the prevalence of self‐reported activity‐specific injuries, to identify the relations between injury profile and different types and patterns of physical activity and to assess whether gender is a modifying variable in that connection. Four hundred and fifty‐seven men and women aged 20–35 years participated in this cross‐sectional study. A questionnaire was used to evaluate the types and patterns of physical activity performed in the 12 months preceding the study and sports injuries sustained during that time. One hundred and ninety of the 457 subjects reported an injury as a result of exercising (41.6%). A relationship was found between weight training and injuries of the upper extremity (UE) for men and between spinning classes and knee injuries for women. Among those who participated in weight‐training exercises, more frequent and longer duration exercise was associated with UE injury, and among those who participated in spinning classes more frequent exercise was associated with knee injury. Future injury prevention programs in sport centers should pay special attention to men who participate in weight training and to women who participate in spinning classes.     

Nutritional aspects of women strength athletes

Strength training elicits sports related and health benefits for both men and women. Although sexual dimorphism is observed in exercise metabolism, there is little information outlining the specific nutritional needs of women strength athletes. Many women athletes restrict energy intake, specifically fat consumption, in order to modify body composition, but this nutritional practice is often counter-productive. Compared to men, women appear to be less reliant on glycogen during exercise and less responsive to carbohydrate mediated glycogen synthesis during recovery. Female strength athletes may require more protein than their sedentary and endurance training counterparts to attain positive nitrogen balance and promote protein synthesis. Therefore, women strength athletes should put less emphasis on a very high carbohydrate intake and more emphasis on quality protein and fat consumption in the context of energy balance to enhance adaptations to training and improve general health. Attention to timing of nutrient ingestion, macronutrient quality, and dietary supplementation (for example, creatine) are briefly discussed as important components of a nutritionally adequate and effective strength training diet for women.     

Associations between health behaviours and health related fitness.

OBJECTIVE: To examine relations between health behaviours and health related fitness. METHODS: Subjects were a convenience sample of 350 healthy adults (172 men, 178 women). Covariance analysis adjusted data for significant influences of age and socioeconomic status. Obesity was assessed by anthropometry and body density. Cardiovascular fitness was assessed and various metabolic measurements were made. Questionnaires on physical activity and health related behaviours were completed. RESULTS: Cigarette abstinence was associated with a small abdominal circumference (men) and a low trunk/extremity skinfold ratio (women). Obesity indices (body mass index, total skinfolds, percent fat, and abdominal circumference) were negatively associated with perceived fitness. Leisure activity and exercise frequency were also negatively linked to some obesity indices. Blood glucose, cholesterol, HDL-cholesterol, and triglycerides were favourably influenced by perceived activity, exercise frequency, and perceived fitness, but not by exercise intensity. Abstinence from coffee was associated with a low cholesterol/HDL ratio (men only). Principal component, discriminant, and multiple logistic regression analyses showed only weak clustering of habitual physical activity with other positive health behaviours. CONCLUSIONS: Although multiphasic health promotion programmes are economical, favourable interactions between individual programme elements seem likely to be quite limited.     

Adolphe Abrahams memorial lecture, 1988. Exercise and lifestyle change.

While the evidence for a clustering of health habits is not particularly strong, there are both pedagogic and economic arguments in favour of a multifaceted approach to health education. The present review thus examines the impact of regular physical exercise upon other forms of health behaviour, testing the extent to which an activity programme can be a catalyst of improved lifestyle in both primary and secondary preventive therapy. The conceptual framework of health promotion is examined with particular reference to the models of Skinner, Becker, Fishbein, Triandis and Rokeach. Certain differences are noted between the decision to exercise and the marketing decisions for which Fishbein's model was originally designed. Nevertheless, in its later modifications, it provides a basic framework for understanding how human lifestyle is shaped. Theoretical mechanisms are suggested whereby exercise could influence such behaviours as cigarette smoking, alcohol consumption and drug usage, seat-belt usage, hypertension, body mass, lipid profile, promiscuous sexual behaviour, the carrying of lethal weapons, and acceptance of regular preventive medical examinations. The empirical evidence from both cross-sectional and longitudinal experiments shows a relatively weak association between exercise habits and other desirable forms of health behaviour. Moreover, it is arguable that other forms of health intervention such as smoking withdrawal or dieting might be equally effective as a primary change agent, and much of the observed association between exercise and other health habits could be attributable to a common dependence on demographic and socio-economic factors. On the other hand, the apparent weakness of associations may arise in part from difficulties in measuring both habitual physical activity and other forms of health behaviour, with a resultant attenuation of correlations. Possibly, a stronger association between exercise participation and other favourable health habits would be uncovered if attention were focused upon those forms of endurance exercise currently thought to enhance cardiac health. Given that moderate endurance exercise is also positive and pleasant advice, further examination of the potential of multifaceted but exercise-centered health promotion programmes appears warranted.     

Commuting, leisure-time physical activity, and cardiovascular risk factors in China

PURPOSE: The relationship between both commuting and leisure-time physical activity and selected cardiovascular risk factors was analyzed. METHODS: A cross-sectional survey was carried out in 1996 in urban Tianjin, China. A total of 2002 male and 1974 female subjects aged 15-69 yr completed the survey. Commuting, leisure-time physical activity, body mass index, blood pressure, and cigarette smoking were determined. RESULTS: Doing more than 60 min of commuting physical activity or combined commuting and leisure-time physical activity was related to the highest mean blood pressure and the highest prevalence of hypertension among both genders compared with going to and from work by bus; 31-60 min commuting only or commuting plus leisure-time physical activity was associated with the lowest mean blood pressure in women and the lowest prevalence of hypertension in both genders. Daily time on commuting or leisure-time physical activity was inversely related to mean body mass index and prevalence of overweight among men and prevalence of smoking among both genders. CONCLUSION: The present study suggests that commuting and leisure-time physical activity were favorably associated with cardiovascular risk factors in this Chinese population, except that more than 60 min of physical activity was associated with high blood pressure.     

Influence of physical activity on mortality in elderly with coronary artery disease

PURPOSE: The primary objectives were to 1) examine the dose-response relationship between physical activity and mortality in individuals with CAD, and 2) determine whether the aforementioned relationship is consistent within strata of other personal characteristics. METHODS: Subjects included 1045 elderly men and women with CAD from the Cardiovascular Health Study. In the first set of analyses, the dose-response relationship between baseline leisure-time physical activity level and all-cause mortality risk over 9 yr was determined using Cox proportional hazards regression models. Next, the subjects were stratified based on several different characteristics, and the consistency of the relationship between baseline leisure-time physical activity and mortality risk within the various strata was determined. RESULTS: Baseline leisure-time physical activity was related to all-cause mortality risk in a curvilinear dose-response manner such that greater differences in mortality risk were seen at the lower end of the energy expenditure scale, with a plateau occurring at approximately 4000 kcal x wk(-1). Within various strata of sex, age, smoking, adiposity, self-perceived health status, number of comorbid conditions, and type of CAD; the relative risks of mortality were lower in active participants (>/=1500 kcal x wk(-1)) in comparison with inactive participants (<1500 kcal x wk(-1)). CONCLUSION: This study highlights the inverse graded relationship between physical activity and all-cause mortality in men and women with CAD. Physical inactivity was a risk factor for mortality regardless of whether the subjects were men or women, old or very old, smokers or nonsmokers, lean or overweight, or otherwise healthy or unhealthy.     

Exercise interventions for patients with peripheral arterial disease: a review of the literature

Peripheral arterial disease (PAD) is a common chronic cardiovascular condition that affects the lower extremities and can substantially limit daily activities and quality of life. Lifestyle interventions, including smoking cessation, diet modification, regular physical activity, and pharmacotherapy, are often prescribed to treat patients with PAD. Exercise interventions can be effective in increasing claudication onset time and maximal walking distance. Of the various types of exercise interventions available for patients with PAD, little is known about the differences that may exist between men and women in patient response to such interventions. The purpose of this literature review is to examine the current knowledge of exercise interventions for individuals with mild (Fontaine stages I-II) PAD and to consider any differences that may exist between men and women. Women with PAD present with a different clinical profile compared with men, but respond similarly to an acute bout of exercise and a training program. Patients with PAD should be encouraged to walk regularly; however, more research is needed to determine differences between men and women in their response to various exercise interventions.     

Nutrient intake of physically fit and unfit men and women

OBJECTIVE: Participation in physical activity and following a diet low in fat, saturated fat, and cholesterol and high in fiber are important in the prevention and treatment of cardiovascular disease and other health problems. Despite the importance of both behaviors, little is known about the interactive role of diet and physical activity. The association between physical activity and diet has been studied, but data on the association between cardiorespiratory fitness (CRF), which is an objective measure of habitual physical activity, and diet are lacking in adults. This report examines nutrient intakes of men and women across low, moderate, and high fitness categories and compares the intakes to national dietary recommendations. It is the first step in examining the relationship between diet, CRF, and morbidity and mortality endpoints in the Aerobics Center Longitudinal Study (ACLS). METHODS: Between 1987 and 1995, 7959 men and 2453 women participating in the ACLS provided 3-d diet records and completed a preventive medical examination. CRF was measured using a maximal exercise test, anthropometric and other clinical variables were measured following a standardized protocol, and lifestyle factors were assessed with a medical history questionnaire. RESULTS: After adjusting for potential confounders, there was a significantly lower percent of energy from fat and saturated fat across low, moderate, and high CRF categories. With additional adjustment for total energy intake, there was a significantly higher dietary fiber intake and a significantly lower cholesterol intake across CRF categories. The percentage of men and women meeting national dietary recommendations was higher at higher CRF levels. CONCLUSIONS: Men and women with higher fitness levels consumed diets that more closely approached national dietary recommendations than their lower fit peers.     

Little effect of long-term, self-monitored exercise on serum lipid levels in middle-aged women.

To study the effect of long-term, self-monitored exercise on physical fitness and serum lipid levels of middle-aged, nonsmoking females, a controlled study was conducted in 33 sedentary Swiss women. Seventeen women were randomly allocated to jog 2h/wk for 4 months on an individually prescribed and heart rate controlled base, whereas 16 women served as controls. Although leisure-time physical activity increased significantly in exercisers compared to controls, the average running distance of 10.9 km/wk was somewhat less than expected. The "net decrease" (4-month change in exercisers minus 4-month change in controls) in the sum of four skin-folds was -4.85 mm (p < 0.05). Four-month changes in serum lipids were generally small and nonsignificant. For example, the net decrease in total triglycerides was -0.2 mmol/l (p = 0.13). Correlational analyses revealed significant associations between changes in the waist-hip ratio and changes in total cholesterol (total-C) or the HDL/total-C ratio (r = 0.44, p < 0.01 and r = -0.29, p < 0.05, respectively). An increase in endurance capacity was associated with an increase in the HDL2-subfraction and in the ratio of HDL/total-C (r = 0.46, p < 0.05 and r = 0.52, p < 0.01). Multivariate linear regression analyses confirmed a change in endurance capacity as the statistically strongest positive predictor of changes in HDL, HDL2 and the HDL/total-C ratio. However, women who used oral contraceptives did not show any favourable lipid changes despite a considerable improvement in endurance capacity. The present training study in healthy, habitually sedentary middle-aged women was not able to show the same beneficial changes in serum HDL concentration as seen in male counterparts, when analyzed according to the principle of intention-to-treat. Exploratory analyses revealed that a too low jogging activity as well as a confounding effect of oral contraceptive use may partially account for the lack of significant changes in serum lipid levels after training.     

Aerobic and resistive exercise modify risk factors for coronary heart disease

An awareness of the health-related benefits of regular physical activity, prudent diet, and cessation of cigarette smoking are some of the mechanisms by which risk factors for coronary heart disease (CHD) and the incidence of complications of atherosclerosis have declined in the American population. Exercise training is associated with improvements in lipid and glucose metabolism that are manifested by enhanced insulin sensitivity, improved glucose tolerance, increased high density lipoprotein cholesterol levels, reduced triglyceride and low density lipoprotein cholesterol levels, and reductions in blood pressure. In addition to reduced risk factors for atherosclerosis, physically conditioned individuals have better cardiovascular function at rest and during exercise than their inactive peers. Thus, exercising training reduces morbidity and mortality from atherosclerotic complications through both direct (cardiovascular) and indirect (risk factor modification) mechanisms. Many studies demonstrate a strong association between regular physical activity and reduced risk for CHD. This article provides a review of risk factors for CHD and the potential health benefits of aerobic and resistive exercise. The time seems apt for the institution of multifactorial cardiovascular risk prevention programs in which aerobic and resistive exercise are combined with prudent diet therapy and smoking cessation to reduce risk factors for CHD.     

Body mass index and mortality: the influence of physical activity and smoking

PURPOSE: To study the association between body mass index (BMI) and mortality, and to evaluate the effect of physical activity during leisure time and smoking on this association in a general male population. METHODS: During 1974-1978, all men aged 35-49 yr living in three Norwegian counties were invited to a cardiovascular screening, and 87.1% attended and had their weight and height measured. Men with recognized cardiovascular diseases, diabetes mellitus, or cancer at screening were excluded. The cohort (N = 22,304) was followed for an average of 16.3 yr with respect to total and cause-specific mortality. RESULTS: During follow-up, 1909 men died. We found a J-shaped association between BMI and total mortality, and the form of association was similar for death from cardiovascular diseases. Although not statistically significant, a J-shaped association was also suggested in never-smokers. Irrespective of BMI level, ex- and never-smokers had lower mortality than current smokers. Obese smoking men had a relative risk of dying of 2.01 (95% CI: 1.29-3.11) compared with obese never-smokers, and a relative risk of 4.55 (95% CI: 3.34-6.20) compared with normal weight never-smokers (BMI 22-24.9 kg x m(-2)). Within each category of physical activity during leisure time, obese men had a similar increased relative risk of death compared with normal-weight individuals. However, the U- to J-shaped association between BMI and mortality seemed to disappear by increasing level of physical activity, but this finding was not significant. CONCLUSION: This study suggests a J-shaped association between BMI and total mortality, also when stratified on smoking habits and physical activity. The suggested linear trend in the most physical active men needs to be reassessed.     

Exercise and smoking habits among Swedish postmenopausal women.

OBJECTIVE: To assess exercise habits and their relation to smoking habits and social and medical factors in postmenopausal women. METHODS: A cross-sectional study with a questionnaire to all 1324 55-56 year old women in Linköping, Sweden. RESULTS: Response rate was 85%. About a third of the women took part in some kind of quite strenuous exercise for at least one hour a week. After a quarter worked out once a week; fewer did swimming and jogging. One in four women smoked. Women who used hormone replacement therapy, who were not smoking and who had a physically light occupation more often took part in strenuous sports. Women who had been treated for malignancies or with back problems exercised to the same extent as women in the general population. CONCLUSION: About a third of the post-menopausal women exercised on a regular basis, if exercise involved in getting to and from work was not counted. Since regular physical exercise has many health benefits, more women should be encouraged to take part in regular physical exercise. Factors probably associated with level of education and general awareness of the importance of a healthy lifestyle positively influenced the likelihood of these women to be physically active on a regular basis. A previous malignant disease or current back problems did not prevent women from taking part in exercise on a regular basis.     

Exercise, energy balance and the shift worker

Shift work is now common in society and is not restricted to heavy industry or emergency services, but is increasingly found amongst 'white collar' occupations and the growing number of service industries. Participation in shift work is associated with increased body mass index, prevalence of obesity and other health problems. We review the behavioural and biological disturbances that occur during shift work and discuss their impact on leisure-time physical activity and energy balance.Shift work generally decreases opportunities for physical activity and participation in sports. For those shift workers who are able to exercise, subjective and biological responses can be altered if the exercise is taken at unusual times of day and/or if the shift worker is sleep deprived. These altered responses may in turn impact on the longer-term adherence to an exercise programme. The favourable effects of exercise on body mass control and sleep quality in shift workers have not been confirmed. Similarly, recent reports of relationships between sleep duration and obesity have not been examined in a shift work context. There is no evidence that exercise can mediate certain circadian rhythm characteristics (e.g. amplitude or timing) for improved tolerance to shift work.Total energy intake and meal composition do not seem to be affected by participation in shift work. Meal frequency is generally reduced but snacking is increased on the night shift. Unavailability of preferred foods in the workplace, a lack of time, and a reduced desire to eat at night explain these findings. 'Normal' eating habits with the family are also disrupted. The metabolic responses to food are also altered by shift work-mediated disruptions to sleep and circadian rhythms. Whether any interactions on human metabolism exist between timing or content of food intake and physical activity during shift work is not known at present.There are very few randomized controlled studies on the efficacy of physical activity or dietary interventions during shift work. Some favourable effects of such interventions on fatigue levels at work have been reported, but biological and behavioural outcomes relevant to long-term health and energy balance have not been studied adequately. In addition, recruitment and retention of research participants for randomized controlled trials of physical activity or dietary interventions have been very difficult. We present a model of the various behavioural and biological factors relevant to exercise and energy balance during shift work as a framework for future research.     

Twenty-five year socioeconomic trends in leisure-time and commuting physical activity among employed Finns

The trend of socioeconomic differences in physical activity is largely unknown in Finland. In this study, we examined socioeconomic trends in leisure-time and commuting physical activity among Finns in 1978–2002. Nationwide data were derived from an annually repeated cross-sectional Finnish Adult Health Behavior Survey. People under the age of 25, students, the unemployed, and retirees were excluded from the analysis. The final data set included 25 513 women and 25 302 men. Socioeconomic variables included education, occupation, and household income. Odds ratios for being physically active and 95% confidence intervals were calculated. People with the lowest income were less leisure-time and commuting physically active. Among women, low occupational status was associated with high commuting physical activity whereas among men such an association was not found. No educational differences among men in leisure-time and commuting physical activity over time were found. Some indications were found that educational differences in leisure-time physical activity among women might have been reversed. Our data suggest that socioeconomic differences in leisure-time and commuting physical activity are quite small and have remained similar between 1978 and 2002.     

Physical activity pattern in men and women at the ages of 16 and 34 and development of physical activity from adolescence to adulthood

The aim of this study was to investigate gender-related differences in physical activity patterns at the ages of 16 and 34 and to analyse those factors that might contribute to an explanation of physical activity habits in adulthood. A randomly selected group, consisting of 220 boys and 205 girls, was tested in 1974 and reinvestigated in 1992 by means of a questionnaire. Eighty-eight percent participated in the reinvestigation. At the age of 16 more boys (69%) than girls (51%) participated in some sports activity in their leisure time. The results showed an overall decrease in participation in vigorous physical activity, although participation in light physical activity remained relatively constant. At the age of 34, there was no difference in overall physical activity between men and women, but the men exercised more vigorously (44% vs. 29%). Early experience of physical activity at the age of 16 decreased the risk of becoming inactive in adulthood. At the age of 34 cohabiting for the men, and having children and high socio-economic class for the women, increased the risk of being physically inactive in adulthood, whereas positive beliefs about health effects of exercise decreased the risk for both men and women.